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<h1 class='fqn'><span class='in-band'>Function <a href='index.html'>memchr</a>::<wbr><a class="fn" href=''>memchr</a></span><span class='out-of-band'><span id='render-detail'>
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               </span><a class='srclink' href='../src/memchr/lib.rs.html#75-106' title='goto source code'>[src]</a></span></h1>
<pre class='rust fn'>pub fn memchr(needle: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a>, haystack: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">&amp;[</a><a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.u8.html">u8</a><a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">]</a>) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>&gt;</pre><div class='docblock'><p>A safe interface to <code>memchr</code>.</p>

<p>Returns the index corresponding to the first occurrence of <code>needle</code> in
<code>haystack</code>, or <code>None</code> if one is not found.</p>

<p>memchr reduces to super-optimized machine code at around an order of
magnitude faster than <code>haystack.iter().position(|&amp;b| b == needle)</code>.
(See benchmarks.)</p>

<h1 id='example' class='section-header'><a href='#example'>Example</a></h1>
<p>This shows how to find the first position of a byte in a byte string.</p>

<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">memchr</span>::<span class="ident">memchr</span>;

<span class="kw">let</span> <span class="ident">haystack</span> <span class="op">=</span> <span class="string">b&quot;the quick brown fox&quot;</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">memchr</span>(<span class="string">b&#39;k&#39;</span>, <span class="ident">haystack</span>), <span class="prelude-val">Some</span>(<span class="number">8</span>));</pre>
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